This book explores the mysteries of the universe, from the depths of the cosmos to the inner workings of the atom. Through a combination of scientific research and philosophical inquiry, Iridium unlocks the secrets of the universe and reveals the hidden truths that lie beneath the
Iridium is a chemical element; it has the symbol Ir and atomic number 77. This very hard, brittle, silvery-white transition metal of the platinum group is considered the second-densest naturally occurring metal, with a density of 22.56 g/cm3 (0.815 lb/cu in) as defined by experimental X-ray crystallography. 191Ir and 193Ir are the only two naturally occurring isotopes of iridium, as well as the only stable isotopes; the latter is the more abundant. It is one of the most corrosion-resistant metals, even at temperatures as high as 2,000 °C (3,630 °F).